Radial brushes are used to remove sprues, clean, debur, polish, radius and finish surfaces of a workpiece. Radial brushes may be used to rotate a plurality of abrasive or nonabrasive fibers relative to the workpiece. The contact of the fibers and the workpiece imparts the energy of the rotating fiber to the surface of the workpiece, thereby conditioning the surface.
A variety of brush configurations have been used to rotate abrasive fibers relative to a workpiece. In each configuration, a plurality of fibers must be attached to a central core for rotation with the core. The core may be of any of a variety of designs including a rim, a planar disk, or a cup. The retention of the individual fibers relative to the rotating core has been achieved by tying or knotting the individual fibers to the core, or embedding the fibers in an adhesive, wherein the adhesive forms the central core as in U.S. Pat. No. 5,155,108 issued to Hettes et al., or bending a fiber about an inner ring.
To increase the dimension of the brush face along the axis of rotation, the inner end of the fibers are compressed along the axis of rotation, so that the outer end of the fibers are splayed to increase the axial dimension of the face. The splay increases the face width of the brush, thereby providing a larger contact area with the workpiece. When a face width greater than a single brush is desired, a plurality of disks are disposed upon a common axis, and axially abutted to increase the face width. However, as the fibers are splayed along the axis of rotation when the trim height decreases, discontinuities in the brush face are formed.
An alternative configuration is disclosed in U.S. Pat. No. 4,457,040 issued to Hettes for an Industrial Wire Cup-Shaped Brush. The Hettes brush includes elongated supports on a knot plate for anchoring the bristles to the supports by elongated loops of a generally complementary shape to the elongated supports. Although the cup brush may be formed in a variety of sizes, the cup-shaped brush provides only a limited face width.
A further attempt to provide a brush includes the retention of a plurality of flaps about the periphery of a disk. The periphery of the disk includes a plurality of sockets and each flap includes a male end for rotatable retention in the socket. Each flap is individually rotatable relative to the disk, as the disk rotates about a central axis. While the flap brush provides an increased face width over the disk or cup brushes, the flaps do not provide a continuous circumferential face. That is in order for the flap brush to operate, there must be sufficient distance between the flaps so that each flap may contact a planar surface against the workpiece.
An alternative abrasive brush is disclosed in U.S. Pat. No. 4,133,147 issued to Swift for Abrasive Brushes and Methods of Making Same. The Swift patent discloses an abrasive brush formed by a knit abrasive filament wound about a core so that the transverse sections of the monofilaments in each strip flare radially outwardly as spokes from the core. However, Swift does not provide a radial brush having a uniform circumferential face.
Therefore, a need exists for a radial brush having an increased face width without a reduced fiber density. A further need exists for a radial brush which may be constructed without restricting the available face width. A need also exists for a method of manufacturing a high density radial abrasive brush.